test(treesitter): make internal lang test pending when necessary

src/nvim/lua/executor.c

@@ -1662,6 +1662,9 @@ static void nlua_add_treesitter(lua_State *const lstate) FUNC_ATTR_NONNULL_ALL
   lua_pushcfunction(lstate, tslua_has_language);
   lua_setfield(lstate, -2, "_ts_has_language");
 
+  lua_pushcfunction(lstate, tslua_remove_lang);
+  lua_setfield(lstate, -2, "_ts_remove_language");
+
   lua_pushcfunction(lstate, tslua_inspect_lang);
   lua_setfield(lstate, -2, "_ts_inspect_language");
 

src/nvim/lua/treesitter.c

@@ -21,6 +21,7 @@
 #include "nvim/lib/kvec.h"
 #include "nvim/log.h"
 #include "nvim/lua/treesitter.h"
+#include "nvim/map.h"
 #include "nvim/memline.h"
 #include "tree_sitter/api.h"
 
@@ -210,6 +211,17 @@ int tslua_add_language(lua_State *L)
   return 1;
 }
 
+int tslua_remove_lang(lua_State *L)
+{
+  const char *lang_name = luaL_checkstring(L, 1);
+  bool present = pmap_has(cstr_t)(&langs, lang_name);
+  if (present) {
+    pmap_del(cstr_t)(&langs, lang_name);
+  }
+  lua_pushboolean(L, present);
+  return 1;
+}
+
 int tslua_inspect_lang(lua_State *L)
 {
   const char *lang_name = luaL_checkstring(L, 1);

test/functional/helpers.lua

@@ -761,6 +761,7 @@ function module.pending_c_parser(pending_fn)
     pending_fn 'no C parser, skipping'
     return true
   end
+  module.exec_lua [[vim._ts_remove_language 'c']]
   return false
 end
 

test/functional/treesitter/language_spec.lua

@@ -27,8 +27,10 @@ describe('treesitter language API', function()
     eq("Error executing lua: .../language.lua:0: no parser for 'borklang' language, see :help treesitter-parsers",
        pcall_err(exec_lua, "parser = vim.treesitter.inspect_language('borklang')"))
 
-    matches("Error executing lua: Failed to load parser: uv_dlsym: .+",
+    if not pending_c_parser(pending) then
-       pcall_err(exec_lua, "parser = vim.treesitter.require_language('c', nil, false, 'borklang')"))
+      matches("Error executing lua: Failed to load parser: uv_dlsym: .+",
+         pcall_err(exec_lua, 'vim.treesitter.require_language("c", nil, false, "borklang")'))
+   end
   end)
 
   it('inspects language', function()